Severe Thunderstorm Warning 285, NWS Quad Cities, IA

Area Forecast Discussion
National Weather Service Quad Cities IA IL
545 PM CDT Fri Aug 21 2026

.KEY MESSAGES...

- Cold frontal passage will bring a risk of strong to severe
  storms through sunset.

- Outside of yet another system centered around Wednesday,
  mainly dry conditions should be seen until late next week.

&&

.SHORT TERM /THROUGH SATURDAY/...
Issued at 153 PM CDT Fri Aug 21 2026

At 18z the cool front was located roughly from KY51 southwest to
KIFA and near KEBS. Ahead of the front was a pre-frontal trof
running from roughly KOVS to near KDSM. Satellite has agitated
clouds along the front between KY51 and KDEH with showers a few
storms developing. There is a layer of low to mid level steep lapse
rates between the trof and front that will sweep through during the
late afternoon/evening with some showers or storms along the
pre-frontal trof. An associated upper level disturbance will
help to enhance the overall mesoscale lift and maintain the
showers/storms along the cool front.

The CAMs are struggling with what will happen late this
afternoon/evening due to the overall weak forcing.

Based on what has occurred so far from satellite/radar, some low end
convection will be seen along the pre-frontal trof. The stronger
convection, associated with the upper level disturbance, will be tied
to the passage of the cool front.

That being said, prime time for strong to severe storms looks to be
3 to 8 PM with the storms quickly decaying in the 8 to 10 PM time
frame.

The primary risks still look to be damaging winds and hail. However,
storm-scale interactions cannot fully rule out the potential of
brief spin-up tornadoes.

The relatively higher severe risk still looks to be along/east of
the Mississippi and the I-80 corridor on north.

After 10 PM quiet conditions will then be seen the remainder of the
night with slowly falling dew points as the cool front slowly exits
the area.

Seasonable temperatures will be seen on Tuesday with breezy
conditions developing around mid-day.

&&

.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
Issued at 153 PM CDT Fri Aug 21 2026

Saturday night through Friday
Assessment...low (20-30%) confidence on rain around Wednesday

Northwest flow aloft will persist through the coming week. The best
chance for any rain looks to be tied to around Wednesday during the
passage of yet another cool front. However, this system will only
have the moisture associated with it. As a result, the model
consensus only has 20-30% chances for rain.

Prior to and after next Wednesday, there will be additional but
weaker upper level disturbances moving through in the flow aloft.
While an isolated shower or storm cannot be ruled out, over 90% of
the area will likely remain dry with near seasonable temperatures.

&&

.AVIATION /00Z TAFS THROUGH 00Z SUNDAY/...
Issued at 541 PM CDT Fri Aug 21 2026

Isolated to scattered SHRA/TSRA will continue through 03z/22
with the better coverage along/east of the Mississippi and
generally north/east of KGBG. Once the cold front passes winds
will drop to under 10 knots overnight. Gusts up to 24 knots will
be possible after 16z/22 across eastern Iowa and northern
Illinois once the nocturnal inversion breaks.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...None.
IL...None.
MO...None.

&&

SHORT TERM...08
LONG TERM...08
AVIATION...08

Hazardous Weather Outlook
National Weather Service Quad Cities IA IL
310 AM CDT Fri Aug 21 2026

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-220815-
Buchanan-Delaware-Dubuque-Benton-Linn-Jones-Jackson-Iowa-Johnson-
Cedar-Clinton-Muscatine-Scott-Keokuk-Washington-Louisa-Jefferson-
Henry IA-Des Moines-Van Buren-Lee-Jo Daviess-Stephenson-Carroll-
Whiteside-Rock Island-Henry IL-Bureau-Putnam-Mercer-Henderson-
Warren-Hancock-McDonough-Scotland-Clark-
310 AM CDT Fri Aug 21 2026

This Hazardous Weather Outlook is for portions of north central
Illinois...northwest Illinois...west central Illinois...east
central Iowa...northeast Iowa...southeast Iowa and northeast
Missouri.

.DAY ONE...TODAY AND TONIGHT

There will be the chance for strong to severe storms today,
especially for areas along and east of the Mississippi River. Storms
are expected to develop through the afternoon hours with damaging
winds and hail being the primary threats, with isolated tornadoes
being secondary. The Storm Prediction Center has highlighted areas
along and east of the river in a Slight Risk, or level 2 of 5, for
severe weather. A Marginal Risk, level 1 of 5, remains for areas
west.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

The probability for widespread hazardous weather is low.

.SPOTTER INFORMATION STATEMENT...

Storm spotter activation is expected today, especially in Illinois
this afternoon and evening.

ERVIN

Special Weather Statement
National Weather Service Quad Cities IA IL
525 PM CDT Fri Aug 21 2026

IAZ051>053-063>065-067-076>078-220100-
Benton-Linn-Jones-Iowa-Johnson-Cedar-Muscatine-Keokuk-Washington-
Louisa-
Including the cities of Vinton, Cedar Rapids, Anamosa, Marengo,
Iowa City, Tipton, Muscatine, Sigourney, Washington, and Wapello
525 PM CDT Fri Aug 21 2026

...Funnel clouds and weak, brief tornadoes possible through 8 PM...

Conditions are favorable for the development of funnel clouds, and
possibly brief, weak tornadoes.  The National Weather Service will
continue to closely monitor the situation, and may issue a
Tornado Warning if the threat increases. If you see a funnel cloud
or tornado, seek shelter indoors and then contact your local law
enforcement agency for relay to the National Weather Service.

Preliminary Local Storm Report
National Weather Service Quad Cities IA IL
747 PM CDT Fri Aug 21 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0730 PM     Tstm Wnd Dmg     1 E Fulton              41.86N 90.15W
08/21/2026                   Whiteside          IL   Public

            Power lines down across the road in Fulton
            Illinois on Illinois 136 towards Clinton.
            Time estimated from radar.

&&

ALE

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